1. Field of the Invention
The present invention relates to a television camera using a solid state image sensor such as a CCD (charge-coupled device), and particularly to a signal processing system for the solid state television camera.
2. Description of the Prior Art
It is very conventional to use an image pickup tube for generating a television signal. A video signal from the image pickup tube is processed through a well-known gain control circuit, phase shifting circuit and so on, so that the resultant processed video signal is ready for use as a standard television signal.
Recently, solid state imaging devices have been developed in many laboratories in accordance with the advancement of semiconductor technology. Among various types of solid state image sensors, a CCD imager is of particular interest.
One difference between a solid state image sensor and a conventional image pickup tube is in the number of available picture elements. That is, in the conventional image pickup tube, the number of picture elements has been considered relatively unlimited. Meanwhile, in the solid state imager, the number of picture elements are clearly defined and the output signal is in the form of a dot-sequential signal.
In a prior art circuit for use in television cameras utilizing a normal image pickup tube, there is a signal processing circuit for the solid state television camera, so that the inherent characteristics of signals derived from the solid state imager have not been effectively utilized. Further, in the prior art, an output signal from the solid state image sensor has been processed by using a conventional gain control circuit and/or a phase shifting circuit.